Torque measuring tool



Allg- 19, 1952 A. c; MILLARD ET AL 2,607,219

TORQUE MEASURING TOOL Aug. 19, 1952 A. c. MILLARD 12T/M 2,607,219

TORQUE MEASURING Toor.

Filed Aug. 23, 1946 4 Sheets-Sheet 2 FIGB .A C. M/LLARD /NVENTORSO C MORR/L ATTORNEY Aug. 19, 1952 A. c. MILLARD ET AL. 2,607,219

ToRQUE MEASURING Toor. Filed Aug. 25, 194e 4. sheets-sheet s .,4. c. M/LARD /NVENTORS- Q C MORR/LL ATTORNEY Aug. 19, 1952 A. c. MILLARD ET AL 2,607,219

ToRQuE MEASURING Toor.

Filed Aug. 2s, 194e 4 Sheets-Sheet 4 .AC M/LLARD mags/foxes@l C MORR/LL B29 @AWM ATTORNEY Patented Aug. 19, 1952 Arthur C. Millard,v Plainfield, N. J., and Otis C. MorrilL Bronxville, N. Y.; said Millard assignor V.to Bell Telephone Laboratories, Incorporated,

New York, N. Y., a corporation vof New York, e and said Morrill assignor to Otis C. Morrlland 'Albert H. lMorrill, copartners, doingbusiness -as Morrill and Morrill, New York, N. Y., a firm Application Augustza, 194s, serial No. 692,614

1 This invention relates to torque measuring devices and more particularly to a precision. tool of the portable type for vmeasuring the torque ap-v plied therethrough in either a `clockwise or counter-clockwise direction, .to rotatable bodies such as nuts, boltsyscrews,` etc., Yand registering the torque applied therethrough by asuitable in- I dicating means. A* e The object of this invention is to provide a precision torque measuringtool which will measure rotatable bodies with' a tolerance so small that for all practical purposes it is negligible.

Another object of thisinvention is to provide a precision torque measuring tool, which due to its novel construction, can be used toA cover a wide range of torque calibrations.

A further object of the invention is the provision of a torque measuringtool which will indi# cate and register the 'amount of torque applied to the object being worked upon.

A still further object of the invention is the` provision of atorque measuring tool which will measure the torque required to rotate a member in Aeither a clockwise or counter-clockwise direction.

still further object of the invention is the provision of a tool for measuring the torqueof rotatable bodies in which the torsion elementis so Vconstructed that the effective length of the element is theV same when it is actuatedin either a'clockwise or a counter-clockwise direction.l

In those instances wherel the successfuloperation ofa piece of equipment'depends upon' the proper degree of tightness Vof the component parts such as screws, nuts, bolts, shafts, andin fact any rotatable body, torque standards are usually set up for the 4particular object involved and some means isusually provided for checking the torque required to tighten or loosen the corn-k e ponent parts of the equipment involved.

Devices for measuring the torque or'force'ap-' plied through a Wrench, screwdriver or other. similar tool have been provided in the past, butA none of these devices are of the so-called k'precision type, since a few inch pounds plus or minus did not make very much diferenceand" was not controlling. However, due to the advent of higher standards in manufacturing and the mass production of instruments and machinesin which the tolerances are set within very close 3 Claims. (Cl. 7S- 139) clockwise direction. Inother words, the tool must be a ,precisioninstrument 01', high order and one which will maintain its high degree -of accuracy for the life ofthe tool. u

Itis also essential that such a tool should provide notonly a means for indicating, in torque units, the'force required formeasuring the torque either in a clockwise or counter-clockwise direction, but should also register such force ony a suitable scale so that itl may be read after the tool 'has returned toits normal position and has' been removed from the object worked upon.

Torque measuring tools in the past have used various types of torsion elements for loading, such as flat springs, wires, coil springs, rods, bars, etc. Howeven'it has been found that'these elements could not be depended upon to maintain their accuracy over a long period of time and therange of suchelements were so limited that aseparate tool had to be provided for each rangejof measurement.

To overcome the shortcomings inexisting tools of this type and to provide a high grade precision type of tool for measuring fand' registering the torque or force required torotate a body in either a clockwisel -orcounter-clockwise direction, an improved 'torque measuring toolhas been -designed. e Y

` The-tool of this invention comprises a tubular handle'or casing having a blade or implement vreyceiving chuck located at one end thereof. the

chuck is rotatablymounted in one end of the housing and has its inner end connectedto a suitable torsion element, which in turn is secured to the opposite end ofthe 'housing' onthe interior thereof. The torsion element of the tool of this invention comprises a precision made helical spring constructed of a high grade spring stock and having its end portions terminating on supporting members r'which are constructed in such afmanner that the effective spral'length along thev neutral `axis of :the spring is the same when itis rotated either in a clockwise direction to expand'thefco'ils or in a counter-clockwise direction to contract them and will Vreturn to its exact normal position. This is dueto the novel type of spring mounting means which connects' the ends of the spring to the clutch and .to the inner end ofthe handle. In order that a wide range of torque measurements -may be made,

springs of various degrees of strength are prothe amount of torque applied to the handle. This band is rotatable and may be set at the desired position in the initial operation of the tool.

In order to facilitate the use of this tool, there is not only provided a rotatably adjustable band, having a circumferential scale thereon, on the head of the tool, but in a modication thereof, means are associated with the rotatable chuck for registering the amount of torque applied when the chuck and the implement mounted therein has returned to its normal or zero position. Thus f' the tool may be removed and areading taken on the scale. This feature is designed to operate when the tool is used either clockwise or'counterclockwise and eliminates the need for observingwhen the object operated thereon, releases under the influence of the torsion means.

In another modification of this tool, the-scale is located on a disc-like member which projects outwardly from the handleat substantially right angles thereto 4thus providing a scale which Vmay be easily read when the tool is being used in fa' vertical position or when the scale on the'side.

Fig. 4 is a cross-sectional View taken on line 4 4 0f Fig. l;

Fig..5 is-a cross-sectional View taken on line 5 5 of Fig. l; N

Fig. 6 is a cross-sectional view taken on line f Fig. '1;is a foreshortened, exploded view in perspective, of rthe tool- Shown inFig. 1; l l l g. 8 is an enlarged view, in perspective, of

the spring or torsion element of the tool of this invention; Fig. 9 is a fragmentary view, with portions broken away, of a modified type of chuck in which a rotatable band, having ahairline mark thereon isprovided, thus enabling the tool to beset and used so that Athe hairline is readily visible; Fig. 10 is an elevational view, partly in section,

of a modified type of indicating scale and pointer,

applied to the chuck end of thev tool.

Fig. 11 is a top plan view of the scale' and pointer shown in Fig. 11. l i

Fig. 12 is a fragmentary cross-.sectional view taken on line I2-"I2 of Fig. 13. Fig. 13 isa fragmentary View partlyin section, illustrating amodied typeof scale andpointer which registers the torque applied .when= the chuck'has returned to its normal position under the influence of the torsion element; and

Fig.v 14 is a view in perspective'of the indicating' pointer and ring employed in the-modification shown in Fig. 13.

The device of our inventionas'shown in the' various guresof the drawings, Acomprises an elongated tubular-handle Aor housing I0 having rotatable mounted on one'endthereof a chuck member I'I said chuck provided with an integral extending sleeve member I2, the central bore of which-is in alignment with an enlarged central bore in the'chuck -I I.' Located'in the end of the' 4 tubular member IB, adjacent the chuck II, are the ball-bearings I3 and I4, which serve to journal the chuck II by supportinggthe sleeve portionl2 thereof. f i 2 Situated between the bearings I3 and I4 and mounted therein and maintaining them in spaced relation, is the sleeve or bushing I5. This sleeve is provided at its inner end with a thickened wall Asection I6 in which a set screw I1 having an extending tip portion I8 is mounted. Mounted on V,the `interior of the sleeve I5 and tting over the sleeve portion I2.cf the chuck II is a bushing I9.

Vwhich is secured to the sleeve I2 and the shaft by means ofthe pin 2l. Located in the bushing I9 is a radial slot 22, which extends circumferentially around said bushing approximately 180 degrees as shown in Fig. 4.

As shown in Fig. l, the tip I8 of the screw I1 extends into the slot 2I"to limit the amount of rotation of the shaft 20 and the chuck Il which is secured thereto by means of the pin 2| within a radius of 180 degrees, or in other words Sill.`

degrees in either directionfrom normal position, thus it will be `readily observed `thatthe chuck I I and its associated parts Vwill befree to rotate.

on thebearings I3 and I4 within the Vlimits of the set screw I1 positioned in the slot 22; this limits the amount of rotation ofthe chuck I I one quarter turn from normal in either. a clockwise or.

counter-clockwise direction.

The shaft 20 is provided at its inner and outer.

ends with shoulderedportionsI 23 and24.- The outer shoulder 24 is adapted to engage vthe shoulder 25 of the bit 26 which is positioned in the central bore of the chuck `l I and held therein by means of the ball 21 which is held in engagement with the groove 28, in the bit 26, by means of the spring 29 and the set screw 33.

As shown in the various figures, a rotatable band 3 I having a scale engraved thereon, is positioned on the outer surface of thehandlev4 Ill adjacent the chuck il, with its graduations reg,-V istering with the hairline on the-chuck II. .'The band 3| as shown in Figs. 1, 3 and 9 is held in position by means .of the expanding ring .3,2 which is located in circumferential ygrooves 33` and 34 in the member IB and the band-3l. f -1 f The inner end of- Y the shaft Y2li@ has its shouldered portion 23 in engagement 'with a shoulder 46 on supporting member 35 to which is secured by means of the pin 36 the inner end-of the spring 31, the outer end 0f this springis secured to supporting member 33 infa similar manner by means of a pin 39.

The inner ends of the spring supporting members and 38, as shown in detail in Fig-8,

are provided with reduced shouldered portionsv 40. and 4I so that the effective length of the spring 31 will be between the pins 36 and 39 and will therefore be extremely accurate and 'exert the same amount of torsion irrespective of the. direction of rotation of the spring 31 and willA return the chuck II to its exact normal' position, or zero setting, no matter which direction the spring is rotated. Without this feature and if this novel type of mounting was not employed the spring 31 would not exert the same amount.

of torsion in each direction since when the spring 31 is tightened by counterclockwise rotation of the handle I0, the diameter of the coils of the spring are reduced, thus causing the inside of the coil to grip the support and to bind thereon and the eiective length is only from the point of contact between the spring and its support By the same token when' at each end thereof.

the: springfisz rotate@ 'as-vtohunwind offiocsen, thefcoiis :for -thespringf'increase and per inf-the coilsvwhichi areii toslidezafround; Thi'slperniitsfthe'ienectiveiength spring where it is secured: to rsiipport.-IVY Thus it can be readily observedthatifrom a givenfriormai j position .or 'zero setting, wheni'theispring'at As shawn in Fig. 1 and infdetail in FigsH-J'an'd! 8, 'ltlieispringl 3J terminates. at-i-ts' -vouterv 1eiidfn the',V supporting ,member -r38asiheretofore 'described. z" This-'supporting memberi'sfprovided with an octagonal shoulder42 and an extending reduced diameter portion 43. The shoulder 42 is positioned in and is embraced by the inner Walls of a bushing or sleeve 44 which is iixedly secured in position in the central bore of the housing l0, at the outer end thereof, thus maintaining in xed position and against rotation the outer end of the spring and its support 38.

- In order that dirt and moisture may be excluded from the interior of the tool, a cap 45 is threadedly mounted in the end of the housing l0. This cap also serves to support the reduced end 43 of the support 38.

In a modified form of chuck or operating head, we have provided as shown in Fig. 9. an adjustable zero setting. This is accomplished by providing a rotating band 41 located in a suitable recess in the chuck Il and having a zero setting hairline 48 engraved thereon. This band is maintained in position by means of a ball 51 which is held in frictional engagement with the inner wall of the band by means of the spring 29. This modified type `or' scale permits a zero setting to be made irrespective of the position of the tool which in some instances may be in such a position that the fixed hairline on the chuck ll would be obscured.

In those instances wherein the tool of this invention is to be used in a vertical or other position which would impair the reading of the scale, as shown in the iigures heretofore described, vve have provided, as shown in Figs. 10

and 11, a disc type of scale which extends outwardly, substantially at right angles from the handle ID of the tool. This scale comprises a disc 49 of plastic or some other suitable material and has provided thereon a series of graduations on its upper or inside surface. The disc 49 is rigidly secured to a band 50 which in turn is frictionally mounted on the chuck il by means of the spring members 5|. These springs will exert suicient pressure to maintain the disc in a fixed position with respect to the chuck l l but will readily permit it to be rotated independently of the chuck for the initial or zero setting. A pointer 52, is affixed to the band 53 which is similarly constructed and which is mounted in a like manner on the body or casing of the handle I0 of the tool.

It has been found that in some instances it is desirable to record or register the amount of force or torque exerted by the tool on a given object and to meet this situation We have pro-v vided a modified type of pointer and scale vas showriffin l .-Fig;v ,113.` Y 'i substance-the operating headfor Y'chuck dmheltooliA Ais fthe same-ifa@ @that shown in Fig. 1 and differs therefrom?in'fthat'ive have providedriin place `of *the- 'hairline r 'onlthe chuckli athi metailiering orf-W'a'shew54A hav-I ing an indicating oi tween "the inner "side o outer sideof the band 31|A With `'the"pointer 55 extending as'hortv l:disc 54 merely has to be rotated 360 degrees so that the pointer is positioned on the opposite side of the member 56.

While We have shown and described herein the preferred form of our invention as applied to a tool in which a screwdriver bit is employed, it is to be understood that various types of implements may be inserted in the chuck and used for registering and measuring the torque of various types of rotatable bodies and that we are not limited to the precise details of construction shown and are only limited by the 'scope of the appended claims.

What is claimed is:

1. A torque measuring tool comprising a casing, an implement holding chuck rotatably mounted on one end thereof, an encircling band having a scale thereon rotatably mounted on said casing adjacent said chuck a. hairline marking on said chuck registering with said scale, a helical spring positioned in said casing, a pair of 'supporting members encompassed by the ends of said spring, each of said supporting members having a relieved shoulder portion at its` inner .l end means on said spring in engagement with said shoulder portions for securingsaid spring thereto, one of said members secured to said chuck and the other to said casing, whereby rotary movement applied to said casing will be imparted to said chuck through said spring. Y

2. A torque measuring tool comprising a casing, an implement holding chuck having an inwardly extending sleeve portion integral there- With rotatably mounted in one Vend thereof, a bushing mounted on said sleeve and having a slot therein, means for securing said bushing to said sleeve, means mounted on said casing and extending thereinto in engagement with said slot to limit the rotation of said bushing, an encircling band having a scale thereon rotatably mounted on said casing adjacent said chuck a hairline marking on said chuck registering with said scale, a helical spring positioned in said casing, a pair of supporting members encompassed by and secured to the ends of said spring, each of said supporting members having a relieved shoulder portion at its inner end, one of said members secured to said chuck and the other aeofnare to said casing whereby rotary movement applied to*` said casing will .be imparted toysaid chuck` through said spring. y

integral therewith, rotatably ymounted iri one endof said casing, ashaft having a shoulderportion on each end thereof positioned ing-said sleeve, a bushing mounted on said sleeve ,and`

said shaft,means on said casing and extending into said circumferential slot to limit the rota-- tion of said casing, a helical-spring in said casing, a pair of supporting members encompassed bythe ends of said spring, each of said supporting members having a relieved shoulder portion at its inner'end, and means on said spring in en gagement with said relievedvshoulder portions for securing said spring-thereto. one o1' said sup# porting members having a shoulder on its outer end in engagement with the shoulder on the inner:

end of said shaft and the other secured to said casing, whereby rotary movement applied to said 'casing will be imparted to said chuck and said saidv implement positioned therein through spring and said shaft. l

i Y ARTHUR C. MIL'L'LAJELD.

OTIS C. MORRILL.

y REFERENCES CITED f Y The following references are file of this patent:

` UNITED STATES APNriizNTs v Name Date Number 'Zimmerman Mar. 28. -1939 of record in the Bucknam .Nov; 15, 196i H111 nlsept, 23, 194i 

